2.1.3: Nucleotides And Nucleic Acids Flashcards
What is a discrete unit in the context of genetics?
A single codon or triplet of bases that codes for one amino acid.
What is a mutation?
A change in the DNA sequence that may affect protein synthesis.
Define transcription.
The process of copying a DNA sequence for one gene into mRNA.
Define translation.
The process where mRNA joins with a ribosome and tRNA brings specific amino acids.
What is a start codon?
The codon that enables the ribosome to attach at the beginning of a gene.
What is a stop codon?
The sequence of three bases that signals the end of translation.
True or False: The genetic code is described as universal.
True
What does it mean for the genetic code to be non-overlapping?
Each base in a gene is part of only one codon.
Where does protein synthesis occur?
On the ribosomes of the rough endoplasmic reticulum (RER).
What are introns?
Sections of DNA that do not code for amino acids and are removed from mRNA.
What are exons?
Sections of DNA that code for amino acids.
Fill in the blank: Introns are removed from mRNA molecules after _______.
[transcription]
What happens to the ribosome when it reaches a stop codon?
It detaches from the mRNA.
What is the purpose of mRNA?
To carry the genetic code from the nucleus to the ribosome.
How does mRNA compare in length to DNA?
mRNA is much shorter than DNA.
What brings the specific amino acid that corresponds to a codon?
tRNA (transfer RNA).
